Python len() function

One of the most common tasks performed during programming is finding the length of a certain object and Python provides a very powerful function called as the len() function that can help you to determine the length (the number of items) of a particular object whether it is a string, list, tuple, etc.

Python len() Syntax

The following is the syntax of the len() method:

Python len() Parameters

The len() function takes only a single parameter:

• s - This parameter refers to the object whose length we want to find and it can be a sequence such as a string, bytes, tuple, list, etc., or a collection such as a dictionary, set, etc.
  

Python len() Return Value

Python len() Examples

Example 1: With sequences like string, tuple, list, etc.

# with list
lst = [1, 2, 3]
print("Length of list is",len(lst))

# with tuple
tup = (1, 2, 3, 4)
print("Length of tuple is",len(tup))

# with range
r = range(0,5)
print("Length of range is",len(r))

# with string
st = 'Coding'
print("Length of String is",len(st))

Output:

Example 2: With collections like dictionary, set, frozen set, etc.

# with dictionary
d1 = {}
print("Length of dictionary is",len(d1))
d2 = { 'a': 1, 'b': 2}
print("Length of dictionary is",len(d2))

# with set
s1 = set()
print("Length of set is",len(s1))
s2 = {1, 2, 3}
print("Length of set is",len(s2))

# with frozen set
fs = frozenset(s2)
print("Length of frozen set is",len(fs))

Output:

Example 3: Exceptions thrown by len() function.

# empty len() function
print(len())

# invalid object passed
import math
print(len(math))

Output:

In this way we have seen the working of the Python len() function and how it can be used to find the length of various objects in Python.